Facebook is 12 today - here's how its look has changed over time
The original domain for Facebook - TheFacebook.com - now redirects to Facebook.com and around one billion people per day visit the website on a desktop, smartphone, or tablet.
Facebook Messenger, an offshoot of Facebook itself that lets users talk to friends, has over 800 million users on its own and WhatsApp, the messaging client Facebook acquired for $19 billion (£13 billion) last year, has around one billion.
The design of Facebook has changed a lot over the years as the social network expanded beyond Harvard, and then to the entire world, with the exception of one or two countries where it is banned, including China.
Here's what the homepage looked like over the years: